From archaeologists to modern-day pagans to Spinal Tap fans, Stonehenge is truly a place of wonder where the demons dwell, where the banshees live and they do live well. The prehistoric monument has been the source of a great deal of speculation over its meaning, purpose and construction. Here are some of the theories surrounding those ancient stones.

Merlin did it

Not as popular a theory among historians as it once was, the Merlin Hypothesis suggests that King Arthur’s pet wizard had Stonehenge constucted with the help of a local giant, the Devil or his own mysterious magic. Notable fabulist Geoffrey of Monmouth was a big supporter of this theory, which was pretty popular into the 14th century.

Merlin manipulates dishware in The Sword in The Stone

It was a very fancy cemetery

Over the years, the remains of 63 different people have been exhumed from the site – in the form of more than 50,000 cremated bone fragments. Apparently the burials occured way back around 3000BC, roughly 100 years after the first stones were placed on the site. Given those rubbery figures, its possible the initial structure was designed as an over-the-top headstone arrangement.

It was designed for healing and pilgrimage

There’s another theory about why those remains were found there, and it’s based on the fact that a lot of them appear to have suffered from illness or injury. This suggests that people saw Stonehenge as a place to travel when you weren’t well, in the hope of getting magical first aid. Further investigation revealed fragments of the first stones had been chipped away, which could have been so people could craft them into healing talismans. (Or they were just touristy vandals.)

Aliens did it

There was once a strong school of thought that held that ancient people were idiots who couldn’t build anything as amazing as the wonders still standing among us today, so they must have had help. Obviously Merlin and his fairy minions are ridiculous, but aliens – well, it makes sense that they would pop down and help our forebears construct monolithic calculators. All you have to do is squint, fudge a few measurements, take liberties in the interpretation of ancient artworks and/or Bible passages, and it makes perfect sense.

Druids used it as a measuring instrument

If you want to know exactly when the Winter Solstice is coming, Stonehenge can help you calculate that. The avenue connecting Stonehenge to the River Avon aligns with the sun that day. Apparently there are key points around the complex that could have been used to predict eclipses, too, which is pretty cool if true. By the way, the “Druids did it” theory began in 1640 but has been pretty well debunked. Sorry.

It was a feel-good collaboration to celebrate unity

And by “unity”, we mean “you’ve all been conquered, now help us build a stone circle so you’ll never forget it”. Everyone except the alien and fairy enthusiasts agree the work of bringing these stones to the site and erecting them in a circle would have required the efforts of many people working together. Under this theory, the Neolithic locals spontaneously banded together to create the ancient equivalent of the Statue of Liberty.

It’s monolithic porn

Look, it seems unlikely, but in 2003 one researcher claimed Stonehenge looked like female genitalia and was meant to celebrate the Earth Mother. This theory requires even more squinting than the alien one.

Stonehenge is explored in the first episode of the new documentary seriesBritain's Ancient Capital: Secrets of Orkney on SBS on Sunday 26 March at 7:30pm on SBS.

More on The Guide:

‘The Night Manager’ is Tom Hiddleston’s audition for James Bond

The longest, most expensive audition tape for 007 ever.

Why Gloria Steinem's 'Woman' is the show everyone needs to see right now

Every now and then you watch a show that makes you want to change the world…

The AIDS hysteria of the 1980s

A newspaper headline in 1981 heralded the dawn of the HIV/AIDS epidemic.

The downsides of discovering a "lost tribe"

"First contact" is a lot more complicated than you think.

By Odin, 'Vikings' season 5 better answer these questions or we're going to lose it

As you can see, we've invested a great deal of emotion in this series...